pkg/host: rework host feature detection/setup

Currently host feature detection/setup code is spread
across platform-independent fuzzer code, pkg/host, pkg/ipc
and executor.
Move this all into pkg/host and show readable info
about features on manager start.

Fixes #46

3 files changed, 24 insertions, 4 deletions

diff --git a/tools/syz-crush/crush.go b/tools/syz-crush/crush.go
index 531b43888..90a7b6185 100644
--- a/tools/syz-crush/crush.go
+++ b/tools/syz-crush/crush.go
@@ -101,7 +101,7 @@ func runInstance(cfg *mgrconfig.Config, reporter report.Reporter, vmPool *vm.Poo
 		return
 	}
 
-	cmd := fmt.Sprintf("%v -executor=%v -repeat=0 -procs=%v -cover=0 -sandbox=%v %v",
+	cmd := fmt.Sprintf("%v -executor=%v -repeat=0 -procs=%v -sandbox=%v %v",
 		execprogBin, executorBin, cfg.Procs, cfg.Sandbox, logFile)
 	outc, errc, err := inst.Run(time.Hour, nil, cmd)
 	if err != nil {
diff --git a/tools/syz-execprog/execprog.go b/tools/syz-execprog/execprog.go
index 40aa521ce..8fc0a4aa1 100644
--- a/tools/syz-execprog/execprog.go
+++ b/tools/syz-execprog/execprog.go
@@ -16,6 +16,7 @@ import (
 	"time"
 
 	"github.com/google/syzkaller/pkg/cover"
+	"github.com/google/syzkaller/pkg/host"
 	"github.com/google/syzkaller/pkg/ipc"
 	"github.com/google/syzkaller/pkg/log"
 	"github.com/google/syzkaller/pkg/osutil"
@@ -53,7 +54,15 @@ func main() {
 		return
 	}
 
-	config, execOpts := createConfig(entries)
+	features, err := host.Check()
+	if err != nil {
+		log.Fatalf("%v", err)
+	}
+	if _, err = host.Setup(features); err != nil {
+		log.Fatalf("%v", err)
+	}
+
+	config, execOpts := createConfig(entries, features)
 
 	var wg sync.WaitGroup
 	wg.Add(*flagProcs)
@@ -195,7 +204,7 @@ func loadPrograms(target *prog.Target, files []string) []*prog.LogEntry {
 	return entries
 }
 
-func createConfig(entries []*prog.LogEntry) (*ipc.Config, *ipc.ExecOpts) {
+func createConfig(entries []*prog.LogEntry, features *host.Features) (*ipc.Config, *ipc.ExecOpts) {
 	config, execOpts, err := ipc.DefaultConfig()
 	if err != nil {
 		log.Fatalf("%v", err)
@@ -226,7 +235,7 @@ func createConfig(entries []*prog.LogEntry) (*ipc.Config, *ipc.ExecOpts) {
 			handled[call.Meta.CallName] = true
 		}
 	}
-	if handled["syz_emit_ethernet"] || handled["syz_extract_tcp_res"] {
+	if features[host.FeatureNetworkInjection].Enabled {
 		config.Flags |= ipc.FlagEnableTun
 	}
 	return config, execOpts
diff --git a/tools/syz-stress/stress.go b/tools/syz-stress/stress.go
index 504e5b58b..29ab24046 100644
--- a/tools/syz-stress/stress.go
+++ b/tools/syz-stress/stress.go
@@ -48,6 +48,14 @@ func main() {
 		log.Fatalf("nothing to mutate (-generate=false and no corpus)")
 	}
 
+	features, err := host.Check()
+	if err != nil {
+		log.Fatalf("%v", err)
+	}
+	if _, err = host.Setup(features); err != nil {
+		log.Fatalf("%v", err)
+	}
+
 	calls := buildCallList(target)
 	prios := target.CalculatePriorities(corpus)
 	ct := target.BuildChoiceTable(prios, calls)
@@ -56,6 +64,9 @@ func main() {
 	if err != nil {
 		log.Fatalf("%v", err)
 	}
+	if features[host.FeatureNetworkInjection].Enabled {
+		config.Flags |= ipc.FlagEnableTun
+	}
 	gate = ipc.NewGate(2**flagProcs, nil)
 	for pid := 0; pid < *flagProcs; pid++ {
 		pid := pid